CWG Issue 1693

This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 118g. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2025-12-19

1693. Superfluous semicolons in class definitions

Section: 11.4 [class.mem] Status: C++14 Submitter: Richard Smith Date: 2013-05-29

[Moved to DR at the February, 2014 meeting.]

The grammar in 11.4 [dcl.fct.def.general] paragraph 1 are (in part):

member-declaration:

function-definition

;

_opt

function-definition:

function-body

function-body:

= default ;

= delete ;

This leads to the following curiosity:

  struct A {
    void f1() = delete;   / #1, ok
    void f2() = delete;;  / #2, ok
    void f3() = delete;;; / #3, error, extraneous semicolon
  };

This could be addressed by moving the semicolon into the productions for function-body for the non-default/delete forms or by adding empty-declaration to the list of member-declaration productions, as is done with namespace-scope declarations.

Proposed resolution (November, 2013):

Change the grammar in 11.4 [class.mem] as follows:

member-declaration:

attribute-specifier-seq_opt decl-specifier-seq_opt member-declarator-list_opt

;

function-definition

~~;_opt~~

using-declaration

static_assert-declaration

template-declaration

alias-declaration

empty-declaration

Change 11.4 [class.mem] paragraph 1 as follows:

...Except when used to declare friends (11.8.4 [class.friend]) or to introduce the name of a member of a base class into a derived class (9.10 [namespace.udecl]), or when the declaration is an empty-declaration, member-declarations declare members of the class, and each such member-declaration shall declare at least one member name of the class.